Data communication system

ABSTRACT

In a system having a plurality of apparatuses connected via a communication line, one apparatus serving as a master unit performs processing on data stored in the other apparatus or apparatuses. The apparatus serving as a master unit generates a work designation message containing a program statement and transmits it to the other apparatuses. The apparatus, receiving the message, performs data processing based on the message and transfers the message to another apparatus in a predetermined order. All the apparatuses connected to the communication line perform processing based on a received message and the processing is completed when the message is returned back to the master unit.

TECHNICAL FIELD

The present invention relates to a data communication system having aplurality of terminals connected to a communication line.

BACKGROUND ART

Conventionally, in a master/slave type POS (point-of-sale) system, themaster unit sequentially designates the respective slave units (e.g.electric cash registers (ECRs) as POS terminals) according to a pollingsystem to enable the collection or consolidation of sales data or thetransferring of set data, or an inquiry with respect to inventory. Thatis, the master unit designates, one by one, the associated ECRs in apredetermined sequence to perform processing such as the collection,consolidation, etc., of data.

In this way, the master unit manages all the slave units and effectsoperations such as the collection and consolidation of data, thusplacing a burden on the master unit. Where the master unit, inparticular, serves as an ECR, there is the problem that the master unitper se cannot perform a registration of sales data until it has finishedeffecting processing on the last slave unit.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide a communication systemhaving a plurality of terminals connected via communication line in amanner such that the burden on a master unit in the processing of thedata is decreased.

According to the present invention, there is provided a datacommunication method which is for use in a data communication systemhaving a plurality of data processing apparatuses connected via acommunication line, wherein one of the data processing apparatusescauses another processing apparatus to execute data processing,-themethod comprising the following steps of:

a) enabling one of the data processing apparatuses serving as a masterunit to generate a-work designation message containing a programstatement for performing predetermined data processing and to transmitthe work designation message to another apparatus;

b) enabling the apparatus which receives the work designation message toperform data processing in accordance with the program statementcontained in the work designation message;

c) enabling the apparatus which receives the work designation message totransmit the work designation message to a next apparatus in apredetermined order; and

d) completing the data processing when the master unit receives, fromthe next apparatus, the work designation message generated therefrom.

According to the present invention, moreover, there is provided a datacommunication system having a plurality of data processing apparatusesconnected via a communication line, each of the data processingapparatuses comprising:

transmitting/receiving means for receiving data from the communicationline and for transmitting data to the communication line;

memory means for storing a work designation message which is received bythe-transmitting/receiving means from another data processing apparatus;

processing means for performing predetermined processing on the basis ofthe work designation message stored in the memory means; and

transferring means for transmitting the work designation message whichis stored in the memory means to a next data processing apparatus inaccordance with a predetermined order.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system arrangement of a POS system to which the presentinvention is applied;

FIG. 2 is a block diagram of each ECR constituting a POS system;

FIG. 3 is a view showing a transmission format of a work designationmessage;

FIG. 4 is a flow chart showing an outline of a whole operation in eachECR;

FIG. 5 is a flow chart showing a step A4 (work designation messageissuance processing) in FIG. 4;

FIG. 6 is a flow chart showing a step A5 (work designation messagetransmitting/receiving prosecution processing) in FIG. 4;

FIG. 7 is a flow chart showing a step C4 (work designation messageanalysis prosecution processing) in a step C4 in FIG. 6;

FIG. 8 is a view for explaining an outline of an operation at a time ofcollecting data;

FIG. 9 is a view illustrating collection result data in the workdesignation message;

FIG. 10 is a flow chart of a second embodiment;

FIG. 11 is a view for explaining the second embodiment according to thepresent invention; and

FIG. 12 is a view for explaining a third embodiment according to thepresent invention.

BEST MODE OF CARRYING OUT THE INVENTION

(First Embodiment)

FIG. 1 is a system arrangement of a POS system. In this POS system,three ECRs serving as POS terminals are connected to a local dedicatedline. Each respective ECR itself performs registration processing onsales data and can serve as a master unit against the other ECRs. Therole of the ECR as the master unit is to designate the collection ofsales data or the consolidation of the sales data relative to the otherECRs or the transferring set data.

By the term “collection of the sales data” is here meant that the ECRserving as the master unit gains access to data on individual items ofgoods stored into a registering file of the ECR. The term “consolidationof the sales data” is intended to mean that the master-ECR gains accessto the consolidated data of the sales of the respective ECRs. The term“transferring of set data” is intended to mean that the master-ECRtransfers data to the other ECRs-so as to add new data to thegoods/price table (Price Look-Up Table) in ECR and rewrite data.

For the ECR serving as the master unit it is necessary to operate a workdesignation key FK on the respective ECRs and designate the kinds ofprocessing. Where, for example, ECR1 designates the collection of salesdata to the other ECRs, the operator designates “collection” on akeyboard on the ECR1 and operates a work designation key FK. Then a workdesignation message is created for “collection” and the message istransferred to the other ECRs; ECR2 and ECR3 in this order to performsales data collection processing. The detail of this processing will beset out below.

FIG. 2 is a schematic block diagram of the respective ECR.

A CPU 11 controls the whole of this ECR in accordance with various kindsof programs stored in a ROM 12 and allows the sales data which is inputfrom a keyboard 13 to be displayed on a display unit 14, to be printedby a printing device 15 on a receipt/journal and to be stored in a filein a RAM 16.

Areas are provided, in the RAM 16, for storing predetermined data andvarious kinds of files. A memory area 16-1 stores ECR No. A registeringfile 16-2 stores individual sales data and includes files on the goodsitems by kind, person in charge, and so on. A file 16-3 stores resultsof consolidations of the sales data. The RAM 16 further has an area 16-4for storing a work designation message and an area 16-5 for storing aflag indicating that the work designation message has been issued.

The keyboard 13 includes, in addition to various types of keys forregistering sales data on the ECR, a work designation key FK 13-1 forserving as a master unit, a “collection” key 13-2, a “consolidation” key13-3 and a “setting” key 13-4 for designating processing.

When the work designation key 13-1 is operated and, for example,“collection” key 13-2 is operated, the work designation message fordesignating data collection to the other ECRs is read out from the ROM12 and stored in the work designation message memory area 16-4. Thismessage is transmitted from a communication interface area 17 to theassociated ECRs. Upon receipt of the message from the ECR serving as themaster unit, the designated ECRs allow the message to be stored in thework designation message memory area 16-4 of their own RMs 16.

The work designation message is comprised of three parts, as shown inFIG. 3, that is, communication data, processing program statement andprocessing data.

The communication data contains ECR No. of a transmission origin and IDrepresenting the kinds of processing. The processing program statementhas its predetermined programs set by “collection”, “consolidation” and“setting” processing. The processing data contains results of collectionand consolidation processing by the associated ECRs, when the message isfor “collection” and “consolidation”, and data set in the Price Look-UpTables when the message is for “setting”.

Then the operation of the POS system will be explained below inaccordance with a flow chart as shown in FIGS. 4 to 7.

FIG. 4 is the flow chart briefly showing the operation of the respectiveECRs.

In a key input waiting state (step A1), if any key is input, then theCPU 11 analyzes the input (step A2). If it is an ordinary registrationoperation by the ECR, registration processing is made for registeringinput sales data in the registration file 16-2 (step A3). If, on theother hand, the work designation message execution key FK is operated,control goes to step A4 and work designation message issuing processingis carried out as will be set out below. Or in the key input waitingstate, if there occurs no keyed-in operation, control goes to step A5and work designation message transmitting/receiving execution processingis carried out as will be set out below.

FIG. 5 shows a flow chart showing the work designation message issuanceprocessing (step A4 in FIG. 4). Based on the-contents of the processingdesignated at a time of operating the work designation message executionkey FK, the CPU 11 enables the creation of a work designation messagefor performing processing on the associated respective ECRs (step B1).

If the ECR1 acts as a master unit and collects data on, for example,“liquors” from the sales data of the whole POS system, the conditions ofthe “liquors” are contained in the “collection” processing programstatement. The processing data contains collection data on this kind ofgoods in the ECR1.

The created work designation message with an ID inherent in itsprocessing is sent to the next ECR (step B2). In this case, the next ECRmeans an ECR designated in a predetermined order, that is, an ECR havingNo. following to that of the ECR now in question. This ID and workdesignation message are stored in the work designation message storagearea 16-4 (step B3) and the issuance origin flag 16-5 is also set (stepB4).

FIG. 6 shows a flow chart showing the work designation messagetransmitting/receiving processing (step A5 in FIG. 4).

The respective ECR checks, at all times, whether the work designationmessage is received or not during operation (step C1). If it isreceived, checking is made to see whether the issuance origin flag is ONor not (step C2). If the work designation message issued from the ECR1is received by the ECR2, since the ECR2 constitutes no work designationmessage issuance origin in this case, control goes to step C4 and thework designation message analysis execution processing is carried out.

FIG. 7 is a flow chart showing the work designation message analysisexecution processing.

It is determined whether or not the registration processing of the salesdata as the function of the ECR is now performed (step D1). If YES, noprocessing corresponding to the work designation message is exacted soas to give priority to the registration processing and history data (inthis case, the registration in-progress indicating data) showing aninability to effect further processing is prepared as shown in step D2and this route goes out of the process. Further, even if not in progressof registration, when it is not possible to perform processingcorresponding to the work designation message (step D3), no dataprocessing corresponding to the work designation message is carried out.If, for example, a department of a processing target is designated as“liquors” in the “collection” work designation message, when there is nocorresponding designation department, no data processing correspondingto the work designation message is carried out. In these cases,processing-unavailability history data indicating these facts isprepared as shown in step D2.

If not in progress of registration, when it is possible to effectprocessing corresponding to the work designation message, the processingprogram is executed in step D4.

When this work designation message analysis execution processing iscompleted, control goes to step C5 shown in FIG. 6, back-up data of thework designation message is prepared and it is stored in the ECR at itsown work designation message storage area 16-4. In this case, at a timeof data collection/consolidation processing, the ECR also stores resultsof its own processing contained in the work designation message as theback-up data in the work designation message storage area 16-4. Thecontent of this work designation message storage area 16-4 is sent tothe next ECR, that is, if this is the ECR2, to the next ECR3 as shown instep C6. A work completion notice is sent to the ECR1 as thetransmission origin as shown in step C7. The processing in such steps C5to C7 is carried out even in the case where the processing correspondingto the work designation message has not been executed as in progress ofregistration.

The ECR1 receives the work completion notice from the ECR2 and, when itdetects its reception (step C8), the contents of the work designationmessage storage area 16-4 is cleared (step C9) so as to cancel theback-up of the work designation message. Backing up the work designationmessage is effected, for temporary storage and holding, until the workcompletion notice is received from its transmission origin. Where nowork completion notice is received a predetermined time from thetransmission of the work designation message (step C10), the followingECR is designated and the work designation message is transmitted instep C11.

In this way, the work designation message is sequentially transferred tothe associated respective ECRs and, finally, the correspondingtransmission origin. In this case, the ECR3 executes the collectionprocessing in accordance with the received message and completes it and,when the ECR1 receives the work completion notice, the ON of theissuance origin flag is detected in step C2 and control goes to step C3and a master processing is performed. That is, the ECR1 designates datacollection to the associated respective ECR's, consolidates thecollected data from these ECRs and prints a result on a journal report.

FIG. 8 shows the processing concept of a whole system at a time of datacollection. Upon issuance of the work designation message, the ECR1transmits the work designation message including the result ofcollection as a processing history to the ECR2. The ECR2 transmits thework designation message including the result of processing by the ECR1as well as a result of collection by itself to the ECR3. The ECR3transmits the work designation message including the results ofprocessing by the ECR1 and ECR2 as well as a result of collection byitself to-the ECR1. In this case, FIG. 9 shows an example of collectionby department and, in an ECR3 in FIG. 9, processing is not possible dueto some reason, such as “in progress of registration”. In this case, ahistory indicating the “unavailability of given processing” is sent, asa result of processing, to an ECR1.

Where, in the POS system thus constructed, the datacollection/consolidation operation, for instance, is to be executed onthe respective ECRs, it is only necessary for an ECR acting as a masterunit to transmit a work designation message to the next ECR. It is,therefore, possible to largely lessen the burden on the master ECR. Itis also possible for the master ECR to perform a registration operationeven if other ECRs perform the data collection/consolidation, etc. . . .Further, in the case of the data consolidation, the data is consolidatedon the respective ECR, thus enabling further lessening of the masterECR's burden.

Further, the processing program statement is contained in the workdesignation message and, even if any ECR not having such a function isincluded in the system, it is possible to execute that function inaccordance with such a program statement. Even if any new function isrequired, it is possible that, without changing the contents of the ROMin the ECR, such a new function can be implemented by the workdesignation message sent from the other ECRs.

In the ECR receiving the work designation message, even where anyprocessing corresponding to the work designation message cannot beperformed due to some reason such as in progress of registration, sincehistory data representing the unavailability of such processing iscontained in the work designation message, it is possible for the masterECR to, when the work designation message is returned back to the masterECR, recognize the reason of such unavailability through the analysis ofthe work designation message.

Since, upon transmission of the work designation message to the nextECR, a corresponding backup is prepared, it is possible to make a repeatrequest even in the case where the work designation message isdisappeared on its transmission path. In the case where a power failure,etc., occurs in the transmission destination, the message can also betransmitted to still another ECR, thus ensuring the positivetransmission of the work designation message.

(Second Embodiment)

In the above-mentioned system, if more terminals (ECRs) are concerned tothe network, more time is required for a master unit to receive areturned-back message after all the processing for requiring more amountof operation as in the collection of data has been ended. In the casewhere first the “collection” is designated and then it is desired toimmediately know a result of “consolidation” while stopping the“collection” designation, it is necessary to interrupt an earlierdesignation.

In order to solve this problem, an additional key for designating aninterruption of an operation is added to the ECR and, by the depressionof this key, a work designation message is prepared for the“interruption” mode. In this case it is only necessary to add aflowchart of FIG. 10 to the flowchart performed by the ECR as shown inFIG. 6.

With reference to FIG. 11 explanation will be given about an ECR1serving as a master unit, designating a “collection” and thendesignating an “interruption”.

In FIG. 11, at a time point in which the ECR1 sends an “interruption”,collection processing is shifted from an (N-1)th ECR to an N-th ECR. AnECR2 determines whether or not it receives an “interruption” messagefrom the ECR1 (step C1, FIG. 10). Then it determines whether or not thismessage is the interruption message (step E1). If YES, the ECR2determines whether or not processing is currently performed based on anearlier work designation message in step E2. In this case, the ECR2 hasalready completed the processing and transfers the interruption messageto an ECR3 (step E3).

Similarly, the message is sequentially transferred from the ECR3 to anECR(N-1) but the processing time required to transferring the message isbrief. Therefore, while an ECR(N) is executing the collection of data,the interruption message is reached from the ECR(N-1) to the ECR(N).When the ECR(N) stops the processing now in progress, it sends theinterruption designation message back to the ECR1 of an issuance origin(step E4). Thus, the ECR1 detects the interruption made.

(Third Embodiment)

A third embodiment according to the present invention will be explainedbelow with reference to FIG. 12.

FIG. 12 shows an outline of the issuance by an ECR1 of a workdesignation message on an inventory inquiry.

Now, in order to give an inquiry to the other ECRs as to the contents ofa given data file, the ECR1 issues a work designation message containingits processing and inquiry data. Then this work designation message issent back to the ECR2. Here, the ECR2 determines whether or not itmanages, under its own control, data required for an inquirycorresponding to the work designation message. If the answer isnegative, the work designation message is sent to the next ECR3. Thenthe ECR3 determines whether or not it manages, under its own control,data necessary for an inquiry in the same way as set out above. Now, ifthe data necessary for an inquiry exists in the data file, the ECR3directly makes an inquiry response to the ECR1 of an issuance originwithout sending the work designation message to the next ECR4. Where aninput is designated as goods inquiry data, for example, not only thenumber (No.) of the goods but also the color, length, width, etc., ofthe goods, if the ECR3 contains the corresponding data in its data file,the ECR3 makes an inquiry response to the ECR1.

In this way, where a given ECR makes an inquiry against another ECR, itis only necessary for an original inquiring ECR to issue the workdesignation message and, in this case, send it to the next ECR only sothat the burden of the original inquiring ECR can be largely alleviated.Since the work designation message contains the corresponding processingprogram, it is also possible to make an inquiry response to the originalinquiring ECR even if the inquired ECR is not equipped with a functionnecessary for the inquiry response.

Although in the respective embodiment the POS system has been explainedas comprising a plurality of ECRs, the master ECR may be comprised of apersonal computer. Further, the present invention is not restricted tothe POS system and may be applied to other data communication systems.

Industrial Applicability

According to the present invention, there is provided a communicationsystem having a plurality of terminals concerned via communication linein which a burden on a master unit in the processing of the data isdecreased.

What is claimed is:
 1. A data communication method for use in a datacommunication system having a plurality of data processing apparatusesconnected via a communication line, wherein one of the data processingapparatuses causes one or more other processing apparatus to executedata processing, the method comprising: enabling one of the dataprocessing apparatuses serving as a master unit to generate a workdesignation message containing a program statement for performingpredetermined data processing, and to transmit the work designationmessage to another apparatus according to a predetermined order;enabling the apparatus which receives the work designation message toperform data processing on data stored in that apparatus in accordancewith the program statement contained in the work designation message;enabling the apparatus which receives the work designation message toreturn a completion notice to the apparatus from which the workdesignation message was transmitted when the data processing iscompleted; enabling the apparatus which receives the work designationmessage to add a result of the data processing performed by thatapparatus to the work designation message; enabling the apparatus whichreceives the work designation message to transmit the work designationmessage, including the result of the data processing performed and addedby that apparatus, to a next apparatus according to the predeterminedorder; enabling the apparatus which has transmitted the work designationmessage to re-transmit the work designation to still another apparatusaccording to the predetermined order when the completion notice is notreceived in a predetermined time period from a previous apparatus towhich the work designation message had been transmitted; and enablingthe master unit to perform data processing based on all results of thedata processing included in the work designation message when the masterunit receives the work designation message from a last apparatusaccording to the predetermined order.
 2. The data communication methodaccording to claim 1, further comprising: enabling the apparatus whichreceives the work designation message to store the work designationmessage therein; and eliminating the stored message when the completionnotice is received from the next apparatus as a transmissiondestination.
 3. The data communication method according to claim 1,wherein the method is applied to a POS system using ECRs as dataprocessing apparatuses, and wherein the data processing performed basedon the work designation message comprises at least one of datacollection and data consolidation of sales data registered by the ECRs.4. The data communication method according to claim 1, wherein themethod is applied to a POS system using ECRs as data processingapparatuses, and wherein the data processing performed based on the workdesignation message comprises data setting in a price look-up tableprovided in each ECR.
 5. The data communication method according toclaim 1, further comprising: enabling the master unit to generate andtransmit a stop message for stopping the earlier transmitted workdesignation message; enabling an apparatus which receives the stopmessage to determine whether or not the data processing corresponding tothe work message is being performed; and transmitting the received stopmessage to the next apparatus when it is determined that the dataprocessing is not being performed, or stopping the data processing andtransmitting the stop message back to the master unit when it isdetermined that the data processing is being performed.
 6. A dataprocessing apparatus connected to a communication line, the apparatuscomprising: transmitter/receiver means for receiving data from otherdata processing apparatuses via the communication line, and fortransmitting data to the other data processing apparatuses via thecommunication line; mode setting means for setting the apparatus to amaster mode in which the apparatus serves as a master unit; masterfunction executing means for, when the master mode is set, generating awork designation message containing a program statement for causinganother apparatus to perform predetermined data processing, transmittingthe work designation message to the other apparatus, and performingmaster processing based on the work designation message after the workdesignation message is returned; and slave function executing means for,when the master mode is not set, performing the predetermined dataprocessing based on the program statement included in the workdesignation message stored in memory means, adding a result of the dataprocessing to the work designation message stored in said memory means,and causing said transmitter/receiver means to transmit the workdesignation message to which the result of the data processing has beenadded to a next apparatus according to a predetermined order; whereinupon completion of the predetermined processing, the slave functionexecuting means causes the transmitter/receiver means to transmit acompletion notice to the data processing apparatus from which the workdesignation message was transmitted; and wherein the slave functionexecuting means causes the transmitter/receiver means to re-transmit thework designation message to still another data processing apparatusaccording to the predetermined order when the completion notice is notreceived in a predetermined time period from a previous data processingapparatus to which the work designation message had been transmitted. 7.The data processing apparatus according to claim 6, further comprising:memory means for, when the master mode is not set, storing the workdesignation message received by the transmitter/receiver means; andwherein upon receipt of the completion notice from a data processingapparatus of a transmission destination of the work designation message,the memory means cancels the work designation message stored therein. 8.The data processing apparatus according to claim 6, wherein the dataprocessing apparatus comprises an ECR apparatus operable in a POSsystem, and wherein the predetermined processing performed based on thework designation message comprises at least one of data consolidation,data collection and data setting.